Disc of rotary mower



FIG. 1 is a front, top, and right side perspective view of a disc of rotary mower, showing my new design;

FIG. 2 is a rear, bottom, and left side perspective view thereof;

FIG. 3 is a front elevational view thereof, the rear elevational view being a mirror image of the front elevational view shown; and,

FIG. 4 is a right side elevational view thereof, the left side elevational view being a mirror image of the right side elevational view shown. 

The ornamental design for a disc of rotary mower, as shown and described. 